U.S. patent application number 15/125926 was filed with the patent office on 2017-01-05 for projected capacitive touch switch panel.
The applicant listed for this patent is NORITAKE CO., LIMITED, NORITAKE ITRON CORPORATION. Invention is credited to Isamu KANDA, Tadami MAEDA, Hitoshi SAKUDA.
Application Number | 20170003823 15/125926 |
Document ID | / |
Family ID | 54071914 |
Filed Date | 2017-01-05 |
United States Patent
Application |
20170003823 |
Kind Code |
A1 |
SAKUDA; Hitoshi ; et
al. |
January 5, 2017 |
PROJECTED CAPACITIVE TOUCH SWITCH PANEL
Abstract
To provide a projected capacitive touch switch panel having
sensor units that are easy to adjust and that minimally reflect
visible light, and furthermore having adequate
environment-resistance properties. A projected capacitive touch
switch panel 1 comprising a glass substrate 2 that has a sensor
unit 3 for performing detection along the X direction, and a glass
substrate 4 that has a sensor unit 5 for performing detection along
the Y direction, in which: the two glass substrates are laminated,
and the sensor units are sandwiched between the glass substrates so
as to face each other; each of the sensor units has a sensor
electrode comprising an Al thin film, and a blackened film
including at least one metal selected from Cr, Mo, and W.
Inventors: |
SAKUDA; Hitoshi; (Mie,
JP) ; KANDA; Isamu; (Mie, JP) ; MAEDA;
Tadami; (Mie, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NORITAKE CO., LIMITED
NORITAKE ITRON CORPORATION |
Aichi
Mie |
|
JP
JP |
|
|
Family ID: |
54071914 |
Appl. No.: |
15/125926 |
Filed: |
March 13, 2015 |
PCT Filed: |
March 13, 2015 |
PCT NO: |
PCT/JP2015/057415 |
371 Date: |
September 13, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 2203/04111
20130101; G06F 3/0446 20190501; G06F 3/044 20130101; G06F 3/0445
20190501; G06F 2203/04103 20130101; G06F 3/0418 20130101 |
International
Class: |
G06F 3/041 20060101
G06F003/041; G06F 3/044 20060101 G06F003/044 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 13, 2014 |
JP |
2014-050403 |
Claims
1. A projected capacitive touch switch panel for detecting a touch
position on a touch screen spread out along an X direction and a Y
direction, characterized in that: the projected capacitive touch
switch panel comprises a glass substrate having a sensor unit for
performing detection along the X direction, and a glass substrate
having a sensor unit for performing detection along the Y
direction, the two glass substrates being laminated, and each of
the sensor units being sandwiched facing each other between the
glass substrates; each of the sensor units has a sensor electrode
formed using sputtering or vacuum deposition, the sensor electrode
comprising an aluminum thin film, and a blackened film laminated on
at least part of the aluminum thin film, the blackened film
containing at least one metal selected from chromium, molybdenum,
and tungsten; one surface of one of the glass substrates
constitutes a touch surface, and in the sensor unit of the
aforementioned glass substrate, the blackened film is formed on the
aforementioned glass substrate on the opposite surface from the
touch surface, and the aluminum thin film is formed on the
blackened film; and in the sensor unit of the other glass
substrate, the aluminum thin film is formed on the surface of the
glass substrate, and the blackened film is formed on the aluminum
thin film.
2. The projected capacitive touch switch panel according to claim
1, characterized in that at least part of the sensor unit has a
translucent part, the translucent part is configured as a lattice
in which the aluminum thin film and the blackened film are
overlapped, and the interstices constitute openings.
3. The projected capacitive touch switch panel according to claim
1, characterized in that the blackened film includes at least one
oxide selected from aluminum oxides and titanium oxides.
4. The projected capacitive touch switch panel according to claim
3, characterized in that the oxide content of the blackened film is
2-16 wt. % with respect to the total amount of the metal and the
oxide.
5. The projected capacitive touch switch panel according to claim
3, characterized in that the blackened film comprises a mixture of
the molybdenum and the aluminum oxide.
6. The projected capacitive touch switch panel according to claim
1, characterized in that the film thickness of the blackened film
is 5-500 nm, and the layer thickness of the aluminum thin film is
500-5000 nm.
Description
TECHNICAL FIELD
[0001] The present invention relates to a projected capacitive
touch switch panel for detecting that a finger of a user, etc., has
approached a given position on a touch surface (XY plane) through a
change in capacitance. In particular, the present invention relates
to a projected capacitive touch switch panel in which a sensor
electrode is provided on a glass substrate.
BACKGROUND ART
[0002] In household electrical appliances, AV devices, PC/OA
devices, industrial machinery, and other electrical devices, touch
switch panels involving projected capacitance schemes are used as
one type of input means. In a projected capacitance scheme, a
plurality of sensor electrodes are arrayed in a grid configuration
along an X direction and a Y direction. Projected capacitive touch
switch panels are typically configured from X-direction and
Y-direction transparent sensor electrode layers formed of indium
tin oxide ("ITO"), a wiring layer leading to the electrodes, an
insulation layer (dielectric layer) provided between transparent
electrodes, a surface-protective layer, and the like, the projected
capacitive touch switch panels having external control units. When
the panel surface is touched by a finger, capacitive coupling
occurs between the sensor electrodes and the finger, changing the
capacitance of the sensor electrodes. The control unit quantifies
the amount of change in the capacitance of the sensor electrodes,
and assesses that a finger has touched [the panel surface] when the
quantity exceeds a predetermined threshold value. This makes it
possible for the control unit to detect which position (XY
coordinates on a plane) has been touched by the finger.
[0003] One structure known as a specific structure of a projected
capacitive touch switch panel is configured such that X-direction
transparent sensor electrodes are formed on one glass substrate, a
Y-direction transparent sensor electrode layer is formed on another
glass substrate, and the glass substrates are superposed so that
one of the glass substrates is positioned between the transparent
sensor electrodes, constituting an insulation layer (dielectric
layer). In another proposed structure, transparent sensor
electrodes are formed of ITO on each of two glass substrates, the
transparent sensor electrodes are arranged so as to face each
other, the glass substrates are superposed with a spacer member
interposed therebetween, and a dielectric material is injected
between the transparent sensor electrodes (see Patent Document 1).
Similarly, a structure was proposed in which transparent sensor
electrodes are formed of ITO on each of two glass substrates, the
transparent sensor electrodes are arranged so as to face each
other, and an insulating adhesive layer is formed between the
transparent sensor electrodes (see Patent Document 2).
PRIOR ARTS LIST
Patent Documents
[0004] Patent Document 1: Japanese Laid-Open Patent Application No.
2006-338668
[0005] Patent Document 2: Registered Utility Model No. 3161738
SUMMARY OF THE INVENTION
Problem to be Solved by the Invention
[0006] In cases in which two glass substrates are used, one of
which being utilized as an insulation layer (dielectric layer)
between sensor electrodes, a gap will form between the electrodes
depending on the thickness of the insulation layer, complicating
adjustment of the sensors by the control unit. Additionally, the
transparent sensor electrodes need to have high transmittance in
order to maintain high display quality, and also need to have low
resistance in order to enable the control unit to detect signal
changes on the order of milliseconds. In cases in which transparent
sensor electrodes formed of ITO are used, as described in Patent
Document 1 and Patent Document 2, it is possible to obtain low
resistance by forming the electrodes on the glass substrates and
increasing the film thickness of the ITO film; however, a problem
is presented in terms of the external appearance because a
yellowish tinge results from the ITO film being increased in
thickness. Therefore, it is not easy to achieve the required low
resistance without adversely impacting the transmittance, etc.
[0007] There exist methods by which an aluminum thin film is used
instead of ITO, and the sensor electrodes are formed in a fine
lattice configuration so as to be substantially transparent to the
naked eye. However, aluminum thin films have very high reflectance
in the visible spectrum (at wavelengths of approximately 400-700
nm), and readily produce glare, adversely affecting the visual
properties (transmittance properties) of the touch screen.
[0008] In the case of a structure in which the transparent sensor
electrodes are not sandwiched between substrates, it is necessary
to provide a protective layer to one sensor-electrode side;
however, this structure may be incompatible with applications in
severe environments.
[0009] The present invention was devised in order to address the
aforementioned problems, and therefore an object of the present
invention is to provide a projected capacitive touch switch panel
having sensor units that are easy to adjust and that minimally
reflect visible light, and furthermore having adequate
environment-resistance properties.
Means for Solving the Problem
[0010] The projected capacitive touch switch panel of the present
invention detects a touch position on a touch screen spread out
along an X direction and a Y direction, characterized in that: the
projected capacitive touch switch panel comprises a glass substrate
having a sensor unit for performing detection along the X
direction, and a glass substrate having a sensor unit for
performing detection along the Y direction, the two glass
substrates being laminated, and each of the sensor units being
sandwiched facing each other between the glass substrates; each of
the sensor units has a sensor electrode formed using sputtering or
vacuum deposition, the sensor electrode comprising an aluminum
(hereinafter referred to as "Al") thin film, and a blackened film
laminated on at least part of the Al thin film, the blackened film
containing at least one metal selected from chromium (hereinafter
referred to as "Cr"), molybdenum (hereinafter referred to as "Mo"),
and tungsten (hereinafter referred to as "W"); one surface of one
of the glass substrates constitutes a touch surface, and in the
sensor unit of the aforementioned glass substrate, the blackened
film is formed on the aforementioned glass substrate on the
opposite surface from the touch surface, and the Al thin film is
formed on the blackened film; and in the sensor unit of the other
glass substrate, the Al thin film is formed on the surface of the
glass substrate, and the blackened film is formed on the Al thin
film.
[0011] The projected capacitive touch switch panel of the present
invention is further characterized in that at least part of the
sensor unit has a translucent part, the translucent part is
configured as a lattice in which the Al thin film and the blackened
film are overlapped, and the interstices constitute openings.
[0012] The projected capacitive touch switch panel of the present
invention is further characterized in that the blackened film
includes at least one oxide selected from Al oxides and titanium
(hereinafter referred to as "Ti") oxides. In particular, the
projected capacitive touch switch panel of the present invention is
further characterized in that the blackened film comprises a
mixture of the Mo and the Al oxide. Additionally, the projected
capacitive touch switch panel of the present invention is further
characterized in that the oxide content in the blackened film is
2-16 wt. % with respect to the total amount of the metal and the
oxide.
[0013] The projected capacitive touch switch panel of the present
invention is further characterized in that the film thickness of
the blackened film is 5-500 nm, and the layer thickness of the Al
thin film is 500-5000 nm.
Effects of the Invention
[0014] Because the projected capacitive touch switch panel of the
present invention detects a touch position on a touch screen spread
out along an X direction and a Y direction, and is configured such
that: the projected capacitive touch switch panel comprises a glass
substrate having a sensor unit for performing detection along the X
direction, and a glass substrate having a sensor unit for
performing detection along the Y direction, the two glass
substrates being laminated, and the sensor units being sandwiched
between the glass substrates so as to face each other; each of the
sensor units has a sensor electrode formed using sputtering or
vacuum deposition, the sensor electrode comprising an Al thin film,
and a blackened film laminated on at least part of the Al thin
film, the blackened film including at least one metal selected from
Cr, Mo, and W; one surface of one of the glass substrates
constitutes a touch surface, and in the sensor unit of the
aforementioned glass substrate, the blackened film is formed on the
surface opposite the touch surface of the glass substrate, and the
Al thin film is formed on the blackened film; and in the sensor
unit of the other glass substrate, the Al thin film is formed on
the surface of the glass substrate, and the blackened film is
formed on the Al thin film, no gap is formed between the two sensor
electrodes, facilitating adjustment of the sensors by a control
unit. Additionally, because each of the sensor units has the Al
thin film and the blackened film formed thereon in the stated
order, the projected capacitive touch switch panel appears black
when viewed from the touch surface, making it possible to minimize
the reflection of visible light. Furthermore, due to the structure
in which the sensor units are sandwiched between the glass
substrates, the metal thin films are protected, making it possible
to enhance the environment-resistance properties.
[0015] Because the projected capacitive touch switch panel of the
present invention is further configured such that at least part of
the sensor unit has a translucent part, the translucent part is
configured as a lattice in which the Al thin film and the blackened
film are overlapped, and the interstices constitute openings, it is
possible to form transparent sensor units that minimally reflect
visible light.
[0016] Because the projected capacitive touch switch panel of the
present invention is further configured such that the blackened
film includes at least one oxide selected from Al oxides and Ti
oxides, it is possible to further reduce the reflectance with
respect to visible light.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a front view and a side view of one example of the
projected capacitive touch switch panel of the present
invention;
[0018] FIG. 2 is a schematic view of an enlarged cross-section of
the panel in FIG. 1;
[0019] FIG. 3 is a partial enlarged view of a sensor unit in FIG.
1;
[0020] FIG. 4 is a graph showing the effects exerted on spectral
characteristics of reflectance by the presence of a blackened film;
and
[0021] FIG. 5 is a graph showing the effects exerted on reflectance
by the mixture composition ratio of the blackened film.
MODE FOR CARRYING OUT THE INVENTION
[0022] One example of the projected capacitive touch switch panel
of the present invention is described on the basis of FIGS. 1-3.
FIG. 1(a) is a front view of the projected capacitive touch switch
panel, and FIG. 1(b) is a side view of the same. As shown in FIG.
1(b), a projected capacitive touch switch panel 1 comprises a
translucent first glass substrate 2 having a sensor unit 3 for
performing detection along an X direction, and a translucent second
glass substrate 4 having a sensor unit 5 for performing detection
along a Y direction, the projected capacitive touch switch panel 1
having a laminated structure in which the first glass substrate 2
and the second glass substrate 4 are bonded together. One surface
of the first glass substrate 2 constitutes a touch surface 2a, the
sensor unit 3 being provided on the opposite surface 2b from the
touch surface 2a. The sensor unit 5 is provided on one surface of
the second glass substrate 4. The sensor unit 3 and the sensor unit
5 are sandwiched facing each other between the two glass
substrates. As shown in FIG. 1(a), the sensor unit 3 for performing
detection along the X direction and the sensor unit 5 for
performing detection along the Y direction are patterned in a
rhomboid shape aligned vertically (Y direction) and horizontally (X
direction). Because the structure has no glass substrate interposed
between the two sensor electrodes, the gap between the sensor
electrodes is dramatically smaller than in a case in which a glass
substrate is interposed therebetween.
[0023] A flexible printed circuit board (FPC) 9 is connected to an
external connection terminal 8, which is connected to the sensor
electrodes of each of the sensor units by wiring 7. A control unit
(not shown) for detecting touch is connected via the FPC 9. A metal
lead frame may be provided in lieu of the FPC 9 in order to enhance
environment-resistance properties. Changing of the capacitance of
the sensor electrodes caused when capacitive coupling occurs
between the electrodes and a finger is utilized in the projected
capacitive touch switch panel of the present invention. A
well-known procedure can be used for the specific detection
procedure, etc., of the control unit.
[0024] FIG. 2 is a schematic view of an enlarged cross-section of
the panel. As shown in FIG. 2, the sensor unit 3 for performing
detection along the X direction has a blackened film 3b formed on
the opposite surface from the touch surface 2a of the first glass
substrate 2, and a sensor electrode 3a comprising an Al thin film
formed on the blackened film 3b. Additionally, the sensor unit 5
for performing detection along the Y direction has a sensor
electrode 5a comprising an Al thin film formed on one
(first-glass-substrate-side) surface of the second glass substrate
4, and a blackened film 5b formed on the Al thin film. When viewed
from the touch surface 2a, both of the sensor units are formed such
that the Al thin film is positioned below the blackened film. The
blackened film absorbs incident light due to interference with
visible light, and thus appears black. The blackened film is a thin
film including a prescribed metal, as described later. The Al thin
film and the blackened film are laminated in order to minimize the
reflection of visible light by the Al thin film; no blackened film
is formed on portions in which the metallic luster (silver color)
of the Al thin film is intentionally exposed in the interest of,
e.g., providing a switch design.
[0025] Additionally, an insulation layer 6 is formed, as necessary,
between the X-side sensor electrode 3a and the Y-side blackened
film 5b. After the insulation layer 6 is formed on one of the
surfaces of the sensor electrode 3a and blackened film 5b, or on
both of these surfaces, the two glass substrates are laminated.
Examples of the insulation layer 6 include coating films formed by
applying an organic resin paste using a dispenser. A thickness of
50-500 .mu.m is suitable for the insulation layer. When the
thickness of the insulation layer exceeds 500 .mu.m, the gap
between the sensor electrodes increases, and a difference is
created between the sensitivity of the X-side sensor and that of
the Y-side sensor.
[0026] FIG. 2 is a schematic view for illustrating the overall
hierarchical relationship between the sensor units positioned
between the two glass substrates. The sensor unit (sensor
electrode) for performing detection along the X direction and the
sensor unit (sensor electrode) for performing detection along the Y
direction are arranged at positions that do not overlap when viewed
in the XY plane. Additionally, in FIGS. 1 and 2, the sensor unit
for performing detection along the X direction is provided to the
touch-surface-side first glass substrate; however, a configuration
may be adopted in which the sensor unit for performing detection
along the Y direction is provided to the first glass substrate, and
the sensor unit for performing detection along the X direction is
provided to the second glass substrate.
[0027] FIG. 3 is a partial enlarged view of a sensor unit. As shown
in FIG. 3, the rhomboid shape of the sensor units as shown in FIG.
1(a) is formed from finer lattice portions. The Al thin films
(sensor electrodes) and the blackened films are overlapped in the
order described above in the lattice portions of the sensor unit 3
and sensor unit 5. The interstices constitute openings 10; the Al
thin film and blackened film are not formed in these portions.
Because a very fine lattice configuration is formed in the lattice
portions, these portions constitute translucent parts that at first
appear to be transparent when viewed. The lattice portions
typically have a line width W of 3-50 .mu.m and a line pitch P of
0.2-1 mm. It is also possible for the shape to be hexagonal,
rectangular or rhomboid (extending vertically), trapezoidal, or any
desired shape, as long as continuous lines are used in its
formation. Because the Al thin film has very high reflectance with
respect to visible light and readily produces glare, the Al thin
film adversely affects the visual properties of the touch surface
when exposed, even when formed in a fine lattice configuration.
However, in the present invention, a prescribed blackened film is
interposed on the Al thin film when viewed from the touch surface,
whereby reflectance with respect to visible light is reduced and
visibility is ensured.
[0028] The first glass substrate 2 and the second glass substrate 4
are translucent insulation substrates; soda-lime glass, quartz
glass, borosilicate glass, alkali-free glass that contains no
alkali components, or the like can be employed as the material
therefor. Soda-lime glass is preferably used due to its high
transmittance and very low cost, such glass being used in window
glass for generic building materials. Each of the glass substrates
is 0.5-5 mm thick, and preferably 1.8-3.0 mm thick.
[0029] The sensor electrodes of each of the sensor units comprise
an Al thin film. The Al thin film is formed by a vacuum process;
i.e., sputtering or vacuum deposition using an Al solid target
(deposition material). The wiring 7 (see FIG. 1(a)) is
simultaneously integrally formed with the sensor electrodes.
Sputtering is more preferably performed as the vacuum process
because uniform films can be formed. Sputtering is a method for
causing accelerated argon ions to collide with a solid target, and
causing the atoms or molecules that are scattered from the target
surface to adhere to the glass substrate to thereby form a
film.
[0030] There is no particular limitation as to the method for
processing the Al thin film into a lattice or other prescribed
shape; however, well-known photo-resolution techniques are
preferably used because it will then be possible to accurately form
the abovementioned fine lattice portions and the wiring connected
to the sensor electrodes. For example, a configuration may be
adopted in which, after the Al thin film is formed by sputtering or
vacuum deposition, a mask layer of an etching pattern is screen
printed using a resist material, and wet-etching is performed using
a prescribed etchant, whereby fine wiring is formed by wet etching.
A thickness of 500-5000 nm is suitable for the Al thin film.
[0031] The blackened film of each of the sensor units comprises a
thin film including (1) at least one metal selected from Cr, Mo,
and W. The blackened film is formed by, e.g., vacuum deposition or
sputtering. For the same reason given with respect to forming the
abovementioned Al thin film, it is more desirable to employ the
sputtering described above for forming the blackened film.
Additionally, wet-etching or the like is performed when processing
the lattice portions; from the standpoint of exceptional
manufacturing efficiency, it is preferable to select, as the
etchant, a liquid (e.g., a phosphoric acid etchant) with which it
is possible to simultaneously etch the materials constituting the
blackened film and the Al thin film. In this case, the lattice
portions of each of the sensor units are formed by simultaneously
etching both materials after the Al thin film and the blackened
film are formed on the glass substrate.
[0032] The blackened film preferably includes a prescribed amount
of (2) at least one oxide selected from Al oxides and Ti oxides.
Examples of Ti oxides include TiO.sub.2, and examples of Al oxides
include Al.sub.2O.sub.3. Including a prescribed amount of these
oxides further reduces the reflectance, as shown in FIG. 5
(described later). When a blackened film comprising a mixture of
(1) at least one metal selected from Cr, Mo, and W and (2) at least
one oxide selected from Al oxides and Ti oxides is formed, the thin
film is formed by vacuum deposition or sputtering using a solid
target (deposition material) comprising this mixture.
[0033] FIG. 4 shows one example of the effects exerted on spectral
characteristics of reflectance by the presence of a blackened film.
In FIG. 4, "with blackened film" indicates that a blackened film
(100 nm) was formed by sputtering using a target comprising a
mixture of Mo and Al.sub.2O.sub.3 (containing 10 wt. % of
Al.sub.2O.sub.3), and a 99%-purity Al thin film (1000 nm) was
formed on the blackened film by sputtering. Conversely, "without
blackened film" indicates that only the Al thin film (1000 nm) from
the above configuration was formed, and no blackened film was
formed. As shown in FIG. 4, in the case in which no blackened film
was provided, the reflectance was dramatically higher than that of
the glass substrate. However, providing the blackened film resulted
in the reflectance being less than that of the glass substrate
alone. It is evident that the spectral characteristics are
substantially flat across all wavelengths and no coloration
occurred.
[0034] In cases in which the blackened film is configured as a
mixture layer comprising (1) at least one metal selected from Cr,
Mo, and W and (2) at least one oxide selected from Al oxides and Ti
oxides, the mixture composition ratio affects the reflectance.
Accordingly, in order to form a film having a desired composition
ratio, it is preferable to use a solid target in the state of a
mixture obtained by mixing the metal and the oxide approximately
uniformly in the desired respective composition ratio in advance,
during film formation. In the blackened film, because the type of
metal in (1) the metal element and the type of metal constituting
(2) the oxide are different, it is impossible to form the film
having the composition described above by methods involving using a
target comprising the metal element or using a mixed gas comprising
argon and oxygen.
[0035] In the mixture composition ratio of the blackened film, an
oxide content of 2-16 wt. % with respect to the total weight (metal
element plus oxide) of the mixture is preferred. When the oxide
content is less than 2 wt. %, the reduction in reflectance might be
unachievable due to the appearance of metallic luster. Conversely,
when the oxide content exceeds 16 wt. %, the reduction in
reflectance might be unachievable due to the appearance of white
turbidity.
[0036] FIG. 5 shows an example of the effects exerted by the
mixture composition ratio of the blackened film. For FIG. 5, a
blackened film (100 nm) was formed on a soda-lime glass substrate
(0.7 mm) by sputtering using a target comprising a mixture of Mo
and Al.sub.2O.sub.3, and a 99%-purity Al thin film (1000 nm) was
formed on the blackened film by sputtering; measurements were made
of changes in the reflectance with respect to visible light (at a
wavelength of 500 nm) that occurred when the amount (wt. %) of
Al.sub.2O.sub.3 in the mixture was changed. As shown in FIG. 5,
when a mixture of Mo and Al.sub.2O.sub.3 is used in the blackened
film, the Al.sub.2O.sub.3 content is preferably 2-16 wt. %, more
preferably 5-15 wt. %, and particularly preferably 8-12 wt. %.
[0037] A film thickness of 5-500 nm is suitable for the blackened
film. When the film thickness is less than 5 nm, blackening is
insufficient, and the reduction in reflectance could be
unachievable. Conversely, when the film thickness exceeds 500 nm,
the effect for reducing reflectance due to the visible-light
interference effect might be unobtainable. A film thickness of
50-200 nm is more desirable. The film thickness is determined for
each of the blackened-film materials in accordance with the
refractive index of the materials.
[0038] The projected capacitive touch switch panel 1 according to
the embodiment shown in FIG. 1 is structured such that the first
glass substrate 2 and the second glass substrate 4 are directly
resin-sealed by the insulation layer 6, without a spacer glass or
other spacer member being interposed therebetween. In the
structure, the two glass substrates are superposed, and the sensor
units are sandwiched between the glass substrates; therefore, the
projected capacitive touch switch panel 1 has mechanical strength
superior to that of a structure comprising a single glass
substrate, and disconnection of the sensor electrodes or of the
wiring can be prevented, even in cases when strong vibration or
high pressure is applied.
[0039] As another embodiment of the projected capacitive touch
switch panel of the present invention, a structure may be adopted
in which a spacer member is provided around the glass
substrates.
[0040] Embodiments of a projected capacitive touch switch panel
were described above with reference to FIGS. 1-3; however, the
configuration of the projected capacitive touch switch panel of the
present invention is not limited to the aforedescribed
embodiments.
INDUSTRIAL APPLICABILITY
[0041] The projected capacitive touch switch panel of the present
invention has sensor units that are easy to adjust and that
minimally reflect visible light; therefore, the present invention
can be suitably utilized in household electrical appliances, AV
devices, PC/OA devices, industrial machinery, and other electrical
devices as input means for such apparatuses. Additionally, having
exceptional environment-resistance properties, the projected
capacitive touch switch panel of the present invention can be
suitably utilized as input means for apparatuses used in severe
environments, such as when installed outdoors or near heaters or a
variety of other industrial machines.
EXPLANATION OF REFERENCE NUMERALS AND SYMBOLS
[0042] 1 Projected capacitive touch switch panel
[0043] 2 First glass substrate
[0044] 3 Sensor unit for performing detection along X direction
[0045] 4 Second glass substrate
[0046] 5 Sensor unit for performing detection along Y direction
[0047] 6 Insulation layer
[0048] 7 Wiring
[0049] 8 External connection terminal
[0050] 9 Flexible printed circuit board (FPC)
[0051] 10 Opening
* * * * *